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B L Powell

Publications and source records attributed to B L Powell.

85 records · Page 5Linked to original sources
PubMed1984

Prospective evaluation of changes in computed cranial tomography in patients with small cell lung carcinoma treated with chemotherapy and prophylactic cranial irradiation.

Computed cranial tomographic scans were performed as part of the pretreatment evaluation and at six- to nine-month intervals posttreatment in 13 patients with small cell lung carcinoma. All patients received 3,000 rad of prophylactic cranial irradiation delivered over two weeks in ten treatment fractions in conjunction with multiagent chemotherapy. Posttreatment scans documented an extraordinarily high frequency of abnormalities including cerebral atrophy (100%), ventricular dilatation (70%), and decreased coefficient of absorption in the white matter (15%). Unexplained neurologic abnormalities developed in four of six patients living at least 15 months after institution of therapy. As the number of long-term survivors of this type of lung cancer increases, the need for prospective comprehensive neuropsychologic assessment to determine the clinical significance of these changes is needed.

Aged↗
PubMed1984

Thyroid cancer.

Thyroid cancers are especially common in patients who have received irradiation to the head and neck region for benign diseases. Well-differentiated papillary and/or follicular carcinomas are the most common types of thyroid cancer. They grow slowly and have a very good prognosis when managed with an appropriate combination of surgical and medical therapy. Other types of thyroid cancer often require more intensive therapy and follow-up. It is especially important to evaluate relatives of patients with medullary thyroid cancer.

Adenocarcinoma↗
PubMed1984

Thorotrast.

Explore the source record for details and available documents.

Female↗
PubMed1984

Thymoma.

Thymomas, with their diverse signs, symptoms and relationships to other systemic diseases, are not infrequently encountered. Histologic classification is now standardized. Thymoma is associated with other disorders, such as myasthenia gravis and pure red cell aplasia. Proper staging, careful histologic evaluation and appropriately selected therapy are necessary to ensure long-term survival.

Anemia, Aplastic↗
PubMed1983

Relationship of progesterone- and estradiol-binding proteins in Coccidioides immitis to coccidioidal dissemination in pregnancy.

Pregnancy is a major risk factor for coccidioidal dissemination. Because rates of Coccidioides immitis growth and endospore release are stimulated in vitro by levels of unbound progesterone and 17 beta-estradiol that are achievable, in vivo, in the sera of pregnant women (i.e., 10(-9) to 10(-8) M), a specific-hormone-binding system in C. immitis was sought. Fungal cytosols were incubated with tritiated steroids plus or minus radioinert steroids to identify specific binding systems. All five strains of C. immitis tested exhibited specific saturable binding for progestin, estrogen, androgen, and (to a lesser extent) corticosterone and glucocorticoid hormone classes. Only low or inconsistent estrogen or androgen binding was found in Blastomyces dermatitidis and Torulopsis glabrata. Cryptococcus neoformans, Paracoccidioides brasiliensis, and non-albicans Candida species showed no binding. Scatchard analysis of progestin and estrogen binding in C. immitis revealed a high-capacity, low-affinity binding system that was unaffected by RNase and DNase, but 40 to 60% degraded by trypsin or heating. Ammonium sulfate precipitation resolved a high-affinity, low-capacity binding system (Kd = 1.24 X 10(-9) to 3.60 X 10(-8) M; number of binding sites = 0.014 to 0.20 pmol/mg of protein). The Kd of this system is sufficient to compete for unbound hormone in the sera of pregnant women. The high-capacity, low-affinity system may serve as a repository for hormone before its attachment to the specific binder. These studies suggest that the effects of nanomolar concentrations of sex hormones on C. immitis may be mediated by a specific cytosol protein-binding system and that stimulatory events observed in vitro may have relevance for the mechanism of coccidioidal dissemination in pregnancy.

Alpha-Globulins↗
PubMed1981

Estrogen receptor measurement in low-protein breast cancer cytosols. A modified charcoal technique.

The assay of estrogen receptor (ER) in human breast cancer biopsies is usually excellent using the dextrancoated charcoal method. If the cytosol protein concentration is below 1 mg/ml, however, underestimation of ER content occurs presumably due to adsorption of ER to the charcoal. This problem can be minimized if 1 mg/ml of bovine serum albumin (BSA) is added to the charcoal solution prior to use.

Biopsy↗
PubMed1981

Improved technique for isolation of Mycobacterium kansasii from water.

A new concentration procedure, together with a new isolation medium, resulted in a 10- to 100-fold increase in the possibility of identifying Mycobacterium kansasii from water samples in comparison to a previously used procedure. In a survey which included both potable and natural water samples from many sites within the state of Texas, nine isolations of high-catalase strains of M. kansasii were obtained from 232 water samples tested. Acid-fast smear results were compared with mycobacterial isolations. An isolate from a river in central Texas is the first high-catalase strain of M. kansasii encountered in a natural water supply. Surveys of water samples from two Texas towns indicate that chlorine levels may influence the number of recoverable mycobacteria in water supplies.

Bacteriological Techniques↗
PubMed1978

Studies on the dissociation of prolactin from mammary tumor membranes.

The dissociation of [125I]iodo-PRL from crude membrane preparations of two transplantable rat mammary carcinomas was studied. At least 1/2 of the specifically bound PRL remains undissociated when membrane pellets are resuspended in buffer. The apparent irreversibly bound fraction can be removed at least partially upon incubation with 6 M urea, but not with 1 M urea. By all the criteria used, the dissociated PRL was undamaged. The physiological importance of this phenomenon may relate to the presence of more than one type of binding site which current techniques do not allow us to distinguish.

Animals↗
PubMed1977

Prolactin binding in ovariectomy-responsive and ovariectomy-nonresponsive rat mammary carcinoma.

Growth of the transplantable mammary tumor, MTW9, in W/Fu rats is greatly enhanced by elevated serum prolactin concentrations. This report compares the prolactin binding to tumor membranes in two mammary tumor strains derived from MTW9. Maximum binding to membranes of both tumors occurred at pH 7.6 after incubation for 30 hr at 4 degrees. The binding was inhibited only by polypeptide hormones that possess lactogenic activity. MTW9-P, an ovariectomy-responsive tumor developed in rats maintained on daily perphenazine injections, had 4-fold-higher prolactin binding than had MTW9MtT, an ovariectomy-nonresponsive tumor developed in rats bearing the mammosomatotropic pituitary tumor, MtTW10. Withdrawal of perphenazine from rats bearing MTW9-P caused a fall to normal of plasma prolactin, no tumor regression, and no significant change in prolactin binding. In contrast, resection of MtT resulted in tumor regression, a fall to normal of serum prolactin, and a nearly 3-fold increase in prolactin binding. Scatchard plots of prolactin binding data yield an apparent affinity constant, Ka, of 1.2 X 109 liters/mole for both tumors. The 4-fold-higher prolactin binding in the ovariectomy responsive variant suggests a positive correlation between ovariectomy response and the number of membrane prolactin-binding sites. No correlation between prolactin sensitivity and prolacting binding is apparent.

Animals↗